CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 29, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Oct. 01, 2011	Jun. 30, 2011	Apr. 02, 2011	Dec. 29, 2012	Dec. 31, 2011	Jan. 01, 2011
Statement of Other Comprehensive Income [Abstract]
Net earnings	$ 37,788	$ 29,769	$ 31,045	$ 22,095	$ 34,559	$ 23,461	$ 19,628	$ 17,825	$ 120,697	$ 95,473	$ 72,867
Other comprehensive income:
Foreign currency translation adjustments									5,873	(10,769)	599
Pension liability adjustment, net of tax of $(137)									2,018	(5,145)	(187)
Unrealized gain on interest rate swaps, net of tax $(149)									244	(586)	423
Comprehensive income									$ 128,832	$ 78,973	$ 73,702